Devices such as near eye displays are known. Such devices enable images from image sources such as displays or scanners to be provided proximate to the eye of a user. Such devices may be used to implement virtual or augmented reality applications.
In such devices it is useful to align the exit pupils of the device with the pupils of the user. However, the distance between the pupils of the eyes of a user may differ between the different users of such devices. Therefore it is useful to enable the position of the exit pupils of such devices to be adjusted.